As wireless spectrum continues to grow increasingly more crowded, neighboring wireless systems are faced with the challenge of sharing scarce spectral resources with incompatible neighboring systems. For example, in the United States, wireless systems based on the Bluetooth protocol standard occupy the 2.4 GHz to 2.4835 GHz band. However, IEEE 802.11b-based and IEEE 802.11g-based wireless systems also occupy the 2.4 GHz to 2.4835 GHz band. Concurrent operation of Bluetooth and IEEE 802.11 devices in close proximity can adversely affect both systems.
Within this context, it is increasingly common for wireless devices such as smartphones, tablet computers and laptop computers to implement both Bluetooth and IEEE 802.11 wireless technologies within the same device. Evolving consumer preferences put significant pressure on device manufacturers to implement smaller and more aggressive form factors. In order to support both Bluetooth and IEEE 802.11-based systems on the same device, existing solutions implement a time sharing scheme to reduce interference while maintaining reasonable levels of performance.
As a brief aside, existing Bluetooth systems implement a master-slave structure to facilitate communication between devices. For example, the Asynchronous Connectionless Link (ACL) protocol for extant Bluetooth devices implements a so-called “polling” scheme; a master device polls the slave device to determine if the slave device has data available for transaction. The master device waits a prescribed period for a response from the slave device. The polling procedure repeats according to a schedule that is unique for each actively connected Bluetooth device. Typically, the polling schedule repeats over short time intervals which are imperceptible to human users. For example, the polling interval for a Bluetooth keyboard is fast enough to render keystrokes without a perceptible delay. Similarly, polling intervals for Bluetooth mice provide fine enough granularity to avoid tracking artifacts (e.g., a jumpy “pointer”, perceptible lag).
However, existing Bluetooth-compliant devices operate at a relatively low data rate (Bluetooth Version 2.1 with Enhanced Data Rate (EDR) has a maximum rate of 3 Mbits/sec), especially when compared to IEEE 802.11-compliant devices (IEEE 802.11 g can provide data rates up to 54 Mbits/sec). As previously alluded to, allocating more bandwidth (e.g., in the form of time and/or spectral resources) to Bluetooth devices reduces the bandwidth that is available to IEEE 802.11. This can significantly compromise the overall performance of IEEE 802.11 devices, especially in applications which require significant amounts of data.
Consequently, improved apparatus and methods are needed for efficient scheduling of shared resources wireless air interfaces on the same (or proximate) devices (e.g., scheduling of bandwidth resources between Bluetooth and IEEE 802.11 wireless systems on the same mobile device).